W-10: material diversity (presentation-only soil split + slope outcrops)

.claude/status.md

@@ -1,5 +1,5 @@
-task: PR #434 (W-9 final-surface talus_step_final)
-phase: CI pass 2 in flight (dim=128→256 fixture, non-vacuity control removed)
-blocked_on: CI completion (run #29284354893 in_progress)
-next: CI completes → extract v2-golden-arm64 left:/right: → re-pin golden → green CI
-updated: 2026-07-13 23:04
+task: #438 W-10 material diversity (presentation-only soil split + slope outcrops)
+phase: CI
+blocked_on: CI run #29288184040 in progress; code-critic review in progress
+next: (1) CI completes → verify all 4 jobs green; (2) critic completes → resolve verdict; (3) create PR with --base render-r12-terragen-preview; (4) append verdict comment; (5) mark ready-for-review
+updated: 2026-07-13 23:59

v2/crates/world/src/bin/map_dump.rs

@@ -20,6 +20,7 @@ use world::gen::material::MaterialId;
 const HMAX: i64 = 200;
 
 /// Primary-material → RGB palette (top-down surface colour).
+/// Includes W-10 presentation-only discriminants: SoilDry (9), SoilWet (10).
 fn colour(m: u8) -> [u8; 3] {
     match m {
         x if x == MaterialId::Air as u8 => [180, 180, 190], // air (above-surface empty) — pale grey
@@ -31,6 +32,8 @@ fn colour(m: u8) -> [u8; 3] {
         x if x == MaterialId::Tuff as u8 => [172, 150, 138], // volcanic tuff — light brown
         x if x == MaterialId::Till as u8 => [184, 194, 206], // glacial till — grey-blue
         x if x == MaterialId::Water as u8 => [40, 70, 130], // coastal water — blue (W-SIM-7, #423)
+        9 => [64, 96, 42],  // W-10: SoilDry (discriminant 9) — darker/drier soil green
+        10 => [128, 164, 90], // W-10: SoilWet (discriminant 10) — lighter/wetter soil green
         _ => [255, 0, 255],                                  // unknown — magenta
     }
 }
@@ -64,14 +67,15 @@ fn main() {
     std::fs::File::create(&out).and_then(|mut f| f.write_all(&buf)).expect("write ppm");
 
     // Material histogram to stderr — a quick sanity read without opening the image.
-    let mut hist = [0u32; 8];
+    // Covers all discriminants: 0-8 (MaterialId), 9-10 (W-10 presentation-only).
+    let mut hist = [0u32; 11];
     for &m in &fields.surface_material {
-        if (m as usize) < 8 {
+        if (m as usize) < 11 {
             hist[m as usize] += 1;
         }
     }
-    let names = ["Air", "Sand", "Permafrost", "Soil", "Bedrock", "Basalt", "Tuff", "Till"];
-    eprintln!("wrote {out}  ({dim}x{dim}, seed={seed:#x}, all landforms ON)");
+    let names = ["Air", "Sand", "Permafrost", "Soil", "Bedrock", "Basalt", "Tuff", "Till", "Water", "SoilDry", "SoilWet"];
+    eprintln!("wrote {out}  ({dim}x{dim}, seed={seed:#x}, all landforms ON, W-10 enabled)");
     for (i, n) in names.iter().enumerate() {
         if hist[i] > 0 {
             eprintln!("  {n:<10} {:>8}  ({:.1}%)", hist[i], 100.0 * hist[i] as f64 / (dim * dim) as f64);

v2/crates/world/src/bin/w10_phase0.rs

@@ -0,0 +1,112 @@
+//! W-10 Phase-0 measurement: moisture and slope histograms for SoilDry/Soil/SoilWet split.
+//! Usage: w10_phase0 [dim]
+//! Outputs: moisture histogram (deciles), slope histogram (deciles), class share estimates.
+
+use world::gen::caps::classify_and_caps_staged;
+use world::gen::material::MaterialId;
+use world::gen::moisture::moisture_at;
+
+const HMAX: i64 = 200;
+
+fn compute_deciles(values: &[i64]) -> Vec<i64> {
+    if values.is_empty() {
+        return vec![0; 11];
+    }
+    let mut sorted = values.to_vec();
+    sorted.sort_unstable();
+    let n = sorted.len();
+    (0..=10)
+        .map(|i| {
+            let idx = (i * n) / 10;
+            sorted[idx.min(n - 1)]
+        })
+        .collect()
+}
+
+fn main() {
+    let dim: usize = std::env::args()
+        .nth(1)
+        .and_then(|s| s.parse().ok())
+        .unwrap_or(512);
+
+    println!("\n=== W-10 PHASE-0 MEASUREMENT (moisture/slope histograms @dim={}, seeds 1..2) ===", dim);
+
+    for seed in [1u64, 2] {
+        println!("\n--- Seed {} ---", seed);
+
+        // Run the post-W-9 classification (all landforms enabled, talus disabled to match Phase-0 intent).
+        // Actually, we want the POST-talus field since that's what classify uses.
+        let (_, staged, _) = classify_and_caps_staged(
+            seed, HMAX, dim, false, true, true, true, true, true, false, true  // enable_w10=true
+        );
+
+        let _n = dim * dim;
+        let post_deneedle_height = &staged.post_deneedle;
+        let erosion = world::gen::erosion::erode(seed, HMAX, dim, true, true);
+
+        // Collect moisture and slope for Soil cells only
+        let mut soil_moistures = Vec::new();
+        let mut soil_slopes = Vec::new();
+
+        for z in 0..dim {
+            for x in 0..dim {
+                let idx = z * dim + x;
+
+                // Check if substrate is Soil (MaterialId::Soil = 3)
+                let material_byte = erosion.surface_material[idx] as u8;
+                if material_byte != MaterialId::Soil as u8 {
+                    continue; // Skip non-Soil cells
+                }
+
+                // Compute moisture
+                let area = erosion.drainage.area[idx];
+                let moisture = moisture_at(area);
+                soil_moistures.push(moisture);
+
+                // Compute slope
+                let slope = match erosion.drainage.downstream[idx] {
+                    Some(d) => (post_deneedle_height[idx] - post_deneedle_height[d]).max(0),
+                    None => 0,
+                };
+                soil_slopes.push(slope);
+            }
+        }
+
+        // Compute deciles
+        let moisture_deciles = compute_deciles(&soil_moistures);
+        let slope_deciles = compute_deciles(&soil_slopes);
+
+        println!("  Soil cells: {}", soil_moistures.len());
+        println!("  Moisture (0=dry, 1000=wet): deciles = {:?}", moisture_deciles);
+        println!("  Slope: deciles = {:?}", slope_deciles);
+
+        // Test threshold candidates from deciles (target: 40–60% / 25–35% / 15–25%)
+        // Deciles show steep distribution: p50≈10–11, p90≈80–170
+        let candidates: &[(i64, i64, &str)] = &[
+            (15, 80, "CANDIDATE-A"),
+            (20, 100, "CANDIDATE-B"),
+            (25, 120, "CANDIDATE-C"),
+        ];
+
+        for (dry_thresh, wet_thresh, label) in candidates {
+            let dry_count = soil_moistures.iter().filter(|&&m| m < *dry_thresh).count();
+            let wet_count = soil_moistures.iter().filter(|&&m| m >= *wet_thresh).count();
+            let normal_count = soil_moistures.len() - dry_count - wet_count;
+            let outcrop_count = soil_slopes.iter().filter(|&&s| s >= 5).count();
+
+            println!("  {} (dry<{}, wet>={}): SoilDry {:.1}% | Soil {:.1}% | SoilWet {:.1}% | Outcrop {:.1}%",
+                label, dry_thresh, wet_thresh,
+                100.0 * dry_count as f64 / soil_moistures.len() as f64,
+                100.0 * normal_count as f64 / soil_moistures.len() as f64,
+                100.0 * wet_count as f64 / soil_moistures.len() as f64,
+                100.0 * outcrop_count as f64 / soil_moistures.len() as f64);
+        }
+    }
+
+    println!("\n=== CHOOSE CANDIDATE ABOVE (target: 40–60% / 25–35% / 15–25%) ===");
+    println!("Pick the candidate closest to those shares, then pin:");
+    println!("// Example: if CANDIDATE-B (20/100) gives best distribution:");
+    println!("const SOILDRY_THRESHOLD: i64 = 20;   // Below this -> SoilDry");
+    println!("const SOILWET_THRESHOLD: i64 = 100;  // At/above this -> SoilWet");
+    println!("const OUTCROP_SLOPE_THRESHOLD: i64 = 5;  // Soil* with slope >= this -> Bedrock");
+}

v2/crates/world/src/bin/w9_sweep.rs

@@ -36,7 +36,7 @@ fn phase0_measurement(dim: usize) {
 
     for seed in [1u64, 42] {
         let (_, staged, masks) = classify_and_caps_staged(
-            seed, HMAX, dim, false, true, true, true, true, true, false  // All landforms ON, talus OFF
+            seed, HMAX, dim, false, true, true, true, true, true, false, true  // All landforms ON, talus OFF, enable_w10=true
         );
 
         println!("\nSeed {} (all landforms ON, dim={})", seed, dim);
@@ -66,7 +66,7 @@ fn sweep_measurement(dim: usize) {
 
     // Generate base map once (with all landforms ON, talus OFF to get post-coastal)
     let (_, staged, masks) = classify_and_caps_staged(
-        seed, HMAX, dim, false, true, true, true, true, true, false
+        seed, HMAX, dim, false, true, true, true, true, true, false, true  // enable_w10=true
     );
 
     // BASELINE: Measure counts for talus-OFF (post-coastal only)
@@ -116,7 +116,7 @@ fn export_candidates(dim: usize) {
 
     // Generate base map once for staged heights
     let (_, staged, _) = classify_and_caps_staged(
-        seed, HMAX, dim, false, true, true, true, true, true, false
+        seed, HMAX, dim, false, true, true, true, true, true, false, true  // enable_w10=true
     );
 
     // Get production materials from baseline (talus OFF) — materials don't change with talus smoothing